title: Cloning, expression promoter analysis of vasa gene in Japanese flounder (Paralichthys olivaceus).
abstract: Vasa is a DEAD box helicase and has shown essential functions during gametogenesis and embryogenesis. In most species, research revealed a specific expression of vasa gene in the germ cells. Thus, vasa has become the candidate gene in identifying germ cells. In this study, the vasa gene was isolated from gonads of Japanese flounder (Paralichthys olivaceus). In the 11.4kb genomic sequence, 23 exons were identified besides 5' and 3' flanking regions. The promoter region contained several putative TF binding sites which may have the function of regulating vasa expression. Quantitative real-time PCR analysis showed that vasa gene expression was restricted to adult gonads, with a higher level in the ovary. Development expression profiling revealed a maternal deposit and constant embryonic expression at early stages, but the relative mRNA amount decreased after gastrula. Nine other PoVasa transcripts were detected and their expression in gonads and during early development was not all the same, implying potential different functions during gametogenesis or early embryonic development. These results together confirmed the feasibility of using vasa as a marker of germ cells and that vasa gene had an important role in spermatogenesis and oogenesis. Furthermore, our study laid the groundwork for identifying fish primordial germ cells (PGCs) and investigating germ cell biology.
authors.affiliation: College of Marine Life Sciences, Ocean University of China, #5 Yushan Road, Qingdao 266003, China; Key Laboratory of Marine Genetics and Breeding, Ministry of Education, #5 Yushan Road, Qingdao 266003, China.
authors.forename: Xiaomeng
authors.initials: X
authors.lastname: Wu
authors.forename: Zhongkai
authors.initials: Z
authors.lastname: Wang
authors.forename: Jiajun
authors.initials: J
authors.lastname: Jiang
authors.forename: Jinning
authors.initials: J
authors.lastname: Gao
authors.forename: Jing
authors.initials: J
authors.lastname: Wang
authors.forename: Xiaosu
authors.initials: X
authors.lastname: Zhou
authors.forename: Quanqi
authors.initials: Q
authors.lastname: Zhang
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D003001:Cloning, Molecular; D029941:Fish Proteins / Q000737:chemistry / Q000235:genetics*; D005432:Flounder / Q000235:genetics* / Q000254:growth & development; D018507:Gene Expression Regulation, Developmental; D005822:Genetic Vectors / Q000235:genetics; D008969:Molecular Sequence Data; D009928:Organ Specificity; D010063:Ovum / Q000254:growth & development / Q000378:metabolism; D011401:Promoter Regions, Genetic / Q000235:genetics*; D020033:Protein Isoforms / Q000737:chemistry / Q000235:genetics
chemical_list: D029941:Fish Proteins; D020033:Protein Isoforms
keywords: Alternative splicing; Expression profile; GFP; Genomic organization; PGCs; Promoter analysis; Vasa; day post hatching; dph; green fluorescent protein; primordial germ cells; qPCR; quantitative real-time PCR